With changes in lifestyle and an aging population, people are paying more attention to their health and spending more time exercising, and the market for sporting goods and fitness equipment has prospered. Lots of new types of equipment have been introduced. The treadmill, which encompasses 30 percent of the entire fitness equipment market, has become accepted by most people for its simple and regular exercise pattern. The treadmill is also popular for its effectiveness in training the muscle strength of the lower limbs and increasing cardiopulmonary endurance.
The commercial treadmill is typically equipped with a compact digital display that can only provide basic parameters like exercise time, exercise distance, mechanical resistance, mechanical rotation speed, or energy consumption. Due to a lack of information, the user does not receive dynamic information from the lower limbs while running on this kind of treadmill, and the risk of injuries from overuse or overexertion increases dramatically when the user exercises in an abnormal posture. Only a few costly treadmills, such as the Compact Tandem Force-Sensing Treadmill produced by AMTI Co. or the Fully Instrumented Treadmill produced by Bertec Co., can calculate the force and moment around the user's limbs and joints or output the temporal-spatial parameters during exercise. These treadmills are usually used for research.
Although commercial fitness equipment manufacturers realize that dynamic information is crucial for the user, the problems associated with component configuration and signal acquisition render it impossible for them to install sensor components like load sensor, force plate, strain gauge or pressure sensor into the equipment. Moreover, hurdles in signal integration and transmission need to be overcome. Only a few manufacturers with enough resources and capability are qualified to make high quality fitness equipment and the market is restricted by its high price and low consumer acceptance.